| Message ID | 1519657500-15094-9-git-send-email-will.deacon@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Feb 26, 2018 at 03:04:56PM +0000, Will Deacon wrote: > Having asm/cmpxchg.h pull in linux/bug.h is problematic because this > ends up pulling in the atomic bitops which themselves may be built on > top of atomic.h and cmpxchg.h. > > Instead, just include build_bug.h for the definition of BUILD_BUG. We also use VM_BUG_ON(), defined in <linux/mmdebug.h>, which includes <linux/bug.h>. ... so I think we still have some fragility here, albeit no worse than before. We also miss includes for: * <linux/percpu-defs.h> (raw_cpu_ptr) * <linux/preempt.h> (preempt_disable, preempt_enable) * <linux/compiler.h> (unreachable) I'm not sure if those are made worse by this change. Mark. > > Signed-off-by: Will Deacon <will.deacon@arm.com> > --- > arch/arm64/include/asm/cmpxchg.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/cmpxchg.h b/arch/arm64/include/asm/cmpxchg.h > index ae852add053d..bc9e07bc6428 100644 > --- a/arch/arm64/include/asm/cmpxchg.h > +++ b/arch/arm64/include/asm/cmpxchg.h > @@ -18,7 +18,7 @@ > #ifndef __ASM_CMPXCHG_H > #define __ASM_CMPXCHG_H > > -#include <linux/bug.h> > +#include <linux/build_bug.h> > > #include <asm/atomic.h> > #include <asm/barrier.h> > -- > 2.1.4 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Mon, Feb 26, 2018 at 03:48:49PM +0000, Mark Rutland wrote: > On Mon, Feb 26, 2018 at 03:04:56PM +0000, Will Deacon wrote: > > Having asm/cmpxchg.h pull in linux/bug.h is problematic because this > > ends up pulling in the atomic bitops which themselves may be built on > > top of atomic.h and cmpxchg.h. > > > > Instead, just include build_bug.h for the definition of BUILD_BUG. > > We also use VM_BUG_ON(), defined in <linux/mmdebug.h>, which includes > <linux/bug.h>. > > ... so I think we still have some fragility here, albeit no worse than before. > > We also miss includes for: > > * <linux/percpu-defs.h> (raw_cpu_ptr) > * <linux/preempt.h> (preempt_disable, preempt_enable) Hmm, we can't include this one because it pulls in linux/bitops.h. I've moved the percpu cmpxchg stuff into asm/percpu.h, but that too is missing the linux/preempt.h #include, so I've added that as well. Generally, I think if we want to clean up our #includes then that's better done as a separate series rather than as a piecemeal effort, which will likely fail to identify many of the underlying problems. Will
On Tue, Feb 27, 2018 at 05:33:23PM +0000, Will Deacon wrote: > On Mon, Feb 26, 2018 at 03:48:49PM +0000, Mark Rutland wrote: > > On Mon, Feb 26, 2018 at 03:04:56PM +0000, Will Deacon wrote: > > > Having asm/cmpxchg.h pull in linux/bug.h is problematic because this > > > ends up pulling in the atomic bitops which themselves may be built on > > > top of atomic.h and cmpxchg.h. > > > > > > Instead, just include build_bug.h for the definition of BUILD_BUG. > > > > We also use VM_BUG_ON(), defined in <linux/mmdebug.h>, which includes > > <linux/bug.h>. > > > > ... so I think we still have some fragility here, albeit no worse than before. > > > > We also miss includes for: > > > > * <linux/percpu-defs.h> (raw_cpu_ptr) > > * <linux/preempt.h> (preempt_disable, preempt_enable) > > Hmm, we can't include this one because it pulls in linux/bitops.h. I've > moved the percpu cmpxchg stuff into asm/percpu.h, but that too is missing > the linux/preempt.h #include, so I've added that as well. > > Generally, I think if we want to clean up our #includes then that's better > done as a separate series rather than as a piecemeal effort, which will > likely fail to identify many of the underlying problems. Sure thing; the above shouldn't hold up this series. Mark.
diff --git a/arch/arm64/include/asm/cmpxchg.h b/arch/arm64/include/asm/cmpxchg.h index ae852add053d..bc9e07bc6428 100644 --- a/arch/arm64/include/asm/cmpxchg.h +++ b/arch/arm64/include/asm/cmpxchg.h @@ -18,7 +18,7 @@ #ifndef __ASM_CMPXCHG_H #define __ASM_CMPXCHG_H -#include <linux/bug.h> +#include <linux/build_bug.h> #include <asm/atomic.h> #include <asm/barrier.h>
Having asm/cmpxchg.h pull in linux/bug.h is problematic because this ends up pulling in the atomic bitops which themselves may be built on top of atomic.h and cmpxchg.h. Instead, just include build_bug.h for the definition of BUILD_BUG. Signed-off-by: Will Deacon <will.deacon@arm.com> --- arch/arm64/include/asm/cmpxchg.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)